Lifting-jack



ALFRED H. JOHNSON,

or NILES, MICHIGAN, i ASSIGNOR 'ro NATIONAL-STANDARD' coMrANY, or NInEs, MIcHIeVAN.

Application mea neeemlm` To all whom t may concern Y f Be it known that I, ALFRED I-I. JOHNSON,

l a citizen ofthe United States, residing at Niles, county of Berrien, and State of Michigan, have invented certain new and useful Improvements in Lifting-Jacks, of

, which the following is' a specification.

This invention relates to improvements' in Alifting jacks.

, The main objects of this invention are First. 'Io provide in allifting jack of the reversing type an improved reversingncontrol means. n

Second. To provide an improved lifting jack of the reversing type: Awhich is veryj .conveniently and easily operated.

Further objects and objects relating tostructural details, will definitely appear I vfrom the detailed description to follow. y

:I accomplish the objects of my invention by the devices and means described in the following specification. The invention is clearly defined and pointed out in, the claims.

A structure which is a preferred embodiment of my. invention isy clearly illustrated in. the accompanying drawing, forming a .part of this-specification, in which:

Figure I isua detaily side elevation of a lifting jack embodying the features of my invention, parts being broken away for convenience inl illustration, the reversingv means being shown `in inoperative position.

Fig. II is a detail side elevation correv spond to F ig. I with the reversing means in operative position. f

- Fig. IIIk 's a detail view of the inner end of the actuating leverfshowingthe arrangement of the lifting pawl thereon.

Fig. IV is la detail transverse section through the actuating lever on line corresponding to line 4-4 of Fig. I.

Fig. V is a detail' ide elevation partially" f. in section on linecorresponding toline 5- 5 form of jack.

of Fig. VI showing.v the `embodiment' or adaptation. of my improvements to another f Fig. VI is a `detail view partially in section on line corresponding to line 6-6 of Figf. f f

In the drawing similar reference charac- LIFTING-J'ACK.

. y Srpecicatonof Letters Patent. Patented June 14, `1921,

11 1920. serial Ne. 429,993.

several views, and the sectional viewsy are taken looking in the direction of the little arrows at the ends'ofthesection lines.

Referring to the drawing, theframe 1 is provided 4withja ylifting bar 2. The lifting bar is'provided with a rack 3 with which pinion 4 coacts; the pinion being secured to the ratchet wheel 5,. n e y The .ratchet wheel 5 is driven from kthe pawl 6 mounted onthe inner-end of the actuating levers 7 ivoted at 8. The pivot pin i 9 forthe lever` 7) The holding b awl 10 isfpivoted on the frame at 11 to coact with the ratchet wheel 5. The

the springs being mounted on the stud13 and engaging the pins 14 onthe pawls. Thel reversingmember 15 is pivoted at 16 and provided with upwardly projecting arms 17 and 18, the arm 17 being adaptedto is mounted on ythe frame.

pawls 'are held yieldingly in engagementV kwith thelratchet by means of the springs 12, y

coact with a pin 19ofnthe pawl 6y and the i arm 18 with thepin 14 of the .pawllOwhen kthe reversing member isinoperative position. rIhe reversingmember is actuated by the spring 21,fthe strength of which exceeds thatof the ysprings. 12, so,y that in 'operation it overcounes the tension of thepawlsprings, alternately throwing the pawls out ofenvgagement withthe ratchet wheel when ythey arev freed from the load by the manipulation ofthe lever.

940,433, dated Novemberv 16, 1909.

The actuating lever comprises ahollow n shank i portion 922 andy a handle extension portion 23. This handleextension portieriy maybe rotated in the shank portion and'is .providedwith afispiral groove 24 engaged member 26 which is slidable within f the` n' The action ofthe 'reversing' f member on the pawls is that kof the stru@r ture lshown in the patent toCook"No.

shank, the control membery being slotted kat A refer to Similar parte throughout theative position, as 'shown in Fig.` I, and when frame.

turned in the other direction the control member is released, as shown in'Fig. II.

In the embodiment shown in Figs. V and VI the pawls and 31 coact directly withV the liftingbar32 which is provided with ratchet teeth 33. The pawls 30 and 31'are provided with tripping lingers 34 and 35 respectively, the fingers being pivotally mounted on the pawls and provided with o scribed. The reversing member is provided I claim as new and desire Y ters Patent, 1s:

with an inwardly projecting arm 41 to be engaged by the control member 26, as shown in Fig. VI. The finger 34coacts with an inclined surface 0n the reversing member, indicated by the dotted line 42 when the pawl is lowered, thereby throwing the pawl out of engagement with the rack as soon as the load is released from the pawl, the swinging of the nger by its engagement with the inclined surface placingthe spring 36 under pressure. On the upward movement of the pawl 30 or on the down stroke of the actuating lever, the pin 43 comes into contact with the tripping lever 44, pivoted at 45 on the tripping linger ,35. The lower end of the lever 44 engages the projection 46 on the reversing member, thereby actuating the tripping finger 35 to Vplace its spring under stress, so that as soon as the load is released from the pawl 31 vit is disengaged.

rlhe particular details of this tripping mechanism, however, are notfeatures of my present invention, and I have illustrated the same in this connection in'order to show Vthe adaptability thereof to different forms of jacks.Y

My improved lifting jack is very convenient to use, as for instance, as an automobile jack, as the yjack may be reversed from the endof the operating lever. Y

I have illustrated 'and described twoV embodinientsfor adaptations of my improvements. `While I contemplate several other adaptations, it is believed that the disclosure made will enable those skilled in the art to adapt the same as may be desired.'

Having thus described my invention, what 1. In a. lifting Vjack comprising a frame and lifting bar, the combination of a pair Aof alternately acting pawls provided with Vengaging/springs, a pivotally mounted rieversing member adapted to coact with said pawls, a spring arranged to actuate said reversing member, said spring being of greaterk `strength than the engaging spring of said pawls, an actuating lever, one of said pawls to secure by Let- Y being mounted on said lever, said lever comprising a hollow shank portion pivoted on said frame anda handle portion rotatively mounted in said shank, said handle being provided with a spirally disposedgroove andsaid shank having a pin engaging said groove, whereby when the handle is rotated it is moved longitudinally within the shank,

and a control member for said reversing vmember disposed in said shank for sliding adjustment therein to coact with said handle.

2. In a lifting jack comprising a frame and lifting bar, the combination of a pair ofi alternately acting pawls, a pivotally mounted reversing member adapted to coact lwith said pawls, an actuating lever, one of Vsaid reversing Vmember disposed in said shank for sliding adjustment therein to coact with said handle. l

3. In a liftingjack comprising a frame and lifting bar, the .combination of a pair of alternately acting pawls, a reversing mem- .ber adapted to coact with said pawls, an

actuating lever operatively associated with at lea-st o ne of vsaid pawls, and comprising' a hollow shank portion pivoted on said frame, and a handle portion rotatively Ymounted in said shank, said handle being provided with coengaging parts whereby when the handle is rotatedit is moved lon gitudinally'within the shank, and a longitudinally slottedcontrol member for said reversingmember disposed in said shank for sliding adjustment therein to coact with said handle, and a pin on said shank engaging said slot in said control member.

4..In a lifting jack comprising a frame and lifting bar, the combination of a pair of alternately acting pawls. a reversing mem- 'ber adapted to coactwith said pawls, an

actuating lever operatively associated with at least one of said pawls, and comprisingl a hollow shank portion pivoted on said frame and a handle portion rotatively mounted in said shank, said `handle being provided with coengaging parts, whereby when the handle is rotatedit is moved longitudinally within the shank,and a control member for said -reversing member mounted on said shank.

5. In a lifting jack comprising a frame and a lifting bar,the combination of a'pair of alternately acting pawls provided with engaging springs, a reversing member-adapted-to coact with said pawls, a spring arranged to act on said reversing member, said spring being of greater strength than. the

1,381,125 v i A5 engaging strength of said pavvls, and ian my hand and-seal in the'presence of two operating means for said jack, Comprising a Witnesses. n

lever having a handle portion adapted for f ALFRED H JOHNSON TL, S1 y rotative movement and operatively asso- 5 ciated with said reversing member, Wherebv Witnesses: v it may be held in inoperative position. f n R. W@ SMITH,

In Witness whereof I have hereunto set A. R. RAHN. 

